JOHANNESBURG Africa's brisk economic growth over the past decade has been consumer driven, a much-hyped trend that masks the uncomfortable fact that the region remains far too reliant on commodities.
Sub-Saharan Africa's growth has been second only to Asia and cracked along at 5.8 percent last year, according to a World Bank estimate, if South Africa, the continent's biggest economy, is excluded.
About two-thirds of growth in the past decade has been driven by domestic demand, which has been stoked by a number of factors including the continent's fast-growing and young population. Consumption has had multiplier effects into a range of services including banking and finance.
Yet unlike in Asia, Africa's consumer boom has been financed mostly by income generated from the export of natural resources.
Without developing a manufacturing sector the world's poorest continent has effectively skipped, or missed out on, the industrial revolution that has powered China's rise. And that leaves it vulnerable to a sharp slowdown as the global commodities boom now looks to be faltering.
While commodities in the past decade only accounted for between a quarter and a third of African growth, depending on your measure, most of the $38 billion of Africa's net foreign direct investment inflows in 2012 were into extractive industries.
Natural resources still account for three-quarters of sub-Sahara's exports, according to the World Bank's latest Africa's Pulse analysis of the region's economy.
It notes that the value of exports from the region soared to $420 billion from $100 billion between 2000 and 2011 - a promising trend that is also very much a double-edged sword.
"A lot of the growth in that value has been driven by the commodity boom rather than increased volumes or production," said Russell Lamberti, chief strategist at Johannesburg-based economic consultancy ETM Analytics.
Signals abound that the commodity boom, which accompanied Africa's fastest era of growth, is running out of steam.
Having poured $400 billion into commodities over the past decade, many investors are now selling. The lower airfare and cheaper food that may result will need a long lead time, while many African countries will feel pain in the meantime.
Take fast-growing Angola, Africa's top crude producer after Nigeria. Its exports are worth around 65 percent of its GDP, and oil comprises 98 percent of total exports.
Consumption there has also been growing rapidly and the splurge has been on imports. So any sharp fall in oil production or prices could stymie that boom.
Government income in the big crude exporters would also take a massive hit. In Nigeria, oil and gas accounts for 80 percent of state revenue and 95 percent of foreign exchange.
"Any downturn in the oil price on the international market would certainly lead to lower fiscal revenues, and hence may have an impact on fiscal spending and economic growth," said Thalma Corbett, head of research at NKC Independent Economists.
On the flip side, domestic demand in Africa has been supported by slowing inflation and falling oil prices will curb that further in the region's many crude importers.
EVEN SOUTH AFRICA VULNERABLE
Even South Africa, the biggest, most diverse and developed African economy, remains heavily resource-dependent.
Its gold industry has been in terminal decline for decades as shafts plunge deeper, ore grades decline and costs climb, knocking it from the world's biggest producer by far to number five, according to the World Gold Council.
Yet customs data shows bullion remains its top export by value, worth over 70 billion rand ($7.61 billion) last year or about 10 percent of the country's total exports, according to customs data. Metals and minerals account for well over a third of export earnings.
So South Africa was dangerously exposed when a wave of violent, illegal strikes hit its platinum and gold sectors last year, triggering violence that killed more than 50 people.
Its current account deficit in the last months of 2012 hit 6.5 percent of GDP, as mining exports fell and foreign investment flows dried up because of the labour unrest.
Credit agencies downgraded the country's sovereign rating because of the violence and the rand currency weakened.
One could be forgiven last year for thinking that South Africa was just a commodities story. Yet mining only accounts for around six or seven percent of the country's GDP. Finance, real estate and business services are by far the biggest sector, representing over 20 percent and manufacturing accounts for around 12 percent.
Manufacturing has been in relative decline in South Africa and though it has made some headway elsewhere in the region, it remains tiny on a global scale. From 2000 to 2011, the value of Africa's manufactured goods rose to $33 billion from $13 billion, according to the World Bank.
The region's commodity exports grew far faster and remain worth about 13 times as much by value.
Africa's overall consumption of the past decade, and the growth it has spurred, will clearly not be sustainable if commodity prices continue to come off the boil.
($1 = 9.1941 South African rand)
(Editing by Susan Fenton)